Protective system for heading machines



12, 4 E'. W. HUEBNER ETAL 2,364,716

PROTECTIVE SYSTEM FOR READING MACHINES Filed Feb. 3, 1945 COMPRESSED171k LINE I N V EN TORS tf'rnasl' flaenzr BY [010111 15. jdersan IPatented Dec. 12, 1944 2,384,716 PROTECTIVE SYSTEM FOR HEADING MACHINESErnest W. lluebner and Lowell E. Petersom-Ini dianapolis, 00., ,Inc.,Delaware Ind assignors to P. R. Mallory & Indianapolis, Ind. ,--acorporation of Application February. 3, 1943, Serial'No. $74,598

Claims. (Cl. -11) This invention relates to protective systems formachines, particularly for metal heading machines.

An object of the invention is to improve protec: tive systems formachines.

Other objects of 'the invention will be apparent I from the descriptionand claims.

In the drawing: v

Figure 1 is a diagram of the protective circuit together with adiagrammatic illustration of the operating parts of a heading machinewith which it is associated; Y 1

Figure 2 illustrates afmodification of part of the machine; and

Figure 3 shows a further modification,

In certain types ofmachines for operating on metal stock, it is ofconsiderable importance .to insure that an appropriate length of rawmetal stock be fed into .the machine before each operation. In themaking of small parts such as rivets, etc., from metal rod, wire, strip,tubing, special sections and the like, for example, the rod is fed intothe machine by feed rollers until it reaches a stop. The end section ofthe rod isthen cut oil by the machine and carried to aheading po sitionwhere cooperating die members come. together to press the cut-on sectionof *met'alrod into the'desired shape. U f f If the feeding rollers failto feed in a suflicient length of metal to the machine, a sectionwhichis too short may be cutoff and carried to the dies. Thereistheninsufilcient metal to completely fill the stationary die duringthe coining operation and it is found that the coined piece may notsufficiently fill the die to be held therein by friction when themovable punching die is retracted. If this occurs, thefcrmed piecemaystick to the punching. dieand remain attached to it. When the next rodsection is brought between the dies, this will result in an excess-ofmetal between them and is liable to result in die breakage or damage .tothe machine. It, therefore, becomes of considerable importance to insurethat the required length of rod stock be measured and cut off for eachoperation.

The present invention relates to a protective system for stopping themachine whenever an insuflicient length of rod stock is fed to themachine. 7

Referring to Figure 1, the operating parts of the machine necessary foran'understanding of th invention are shown and include'an electric motorI for driving the machine, a shaft 2 driven former secondary winding 2|through relay I9,

thereby and a flywheel 3 on the shaft. The rod stock 4 isfed into themachine by a pair of feed rollers" 5 driven by a one way clutch 6 whichin turn is driven by a rocker arm I linked to shaft 2 of the machine.Thus as the arm I oscillates back .and forth it advances the rod 4during its motion in one direction, the rod remaining stationary duringthe return motion of the arm.

The rod 4 isfed through an opening in the operating face 8. of themachine until it reaches stop member 9 whereupon a cutter Ill cutsoilthe end section of the rodand an arm ll car ries the cut ofl sectionto a position between stationary. die 12 and movable die I3, which thencome together to coin the rod section into the desired rivet. or otherproduct. Duringnormal operation, the coined rivet remains in thestationary die l2 when the punching die [3 is rear; I I tracted andthepiece is thenejected from die [2 by mechanical plunger l2a or othermeans such" as compressed air. According to the present invention abrake band it is provided on the outer rim of flywheel.

3 to stop themachine. The brake is'operated-by a lever l5 controlledbycompressed air cylinder i l8 supplied from a compressed air line Hunder.

control of valve i8,operated by; solenoid 40 Stop member 9 isinsulatedfrom the restof, the machine. The protective circuitzcomprisesa normally energized protective relay I9 under joint control of a camoperated switch 20 and a :circuit through rod 4 and stop memberfl. The

energizing circuit for relay l9 extends from transthen through normallyclosed contactsof switch I 20 to ground. A second energizing circuit ispos sible inparallel with switch" via conductor 22,. stop member S androd 4 to. ground'in the stop member-"l":

machine framewhenever rod 4 is in contact with gizing' circuitfor-electridniotor I. The back contacts of relay l9 close anoperatingcircuit f r valvecontrol-relay flgwhichcontrols the machine." v

With the machine in. the position shown the energizing circuit for relayI! is closed and hence the front contacts of this'relay are closed. Tooperate the machine, the operator closes starting switch 25momentarily'to close the energizing clay I! asfrontv-v andflbackcontacts-th I front contacts being in the holding circuit fora motorcontrol relay ilwhichcontrols the ener- '2 circuit for motor controlrelay 23 from A. ,C. power line 25. Relay 23, in operating, closes aholding circuit for-itself through its, contacts 21 and thefrontcontacts of relay 19. It alsocloses circuit for motor I through conheenergizing 'tacts 28 thus starting-the iriac'hinein operation." Asshaft2 rotates, rocker arm *1 oscillatesback and forth-advancing rod 4on each travel inthe direction of the arrow. The arm is adjusted to havea small amount of overtravel so that rod 4 reaches stop 9 shortlybefore-arm! reaches; "the end of its travel.

The operating arm of switch2llis disposed in the path of travel-oftheend 29 of-arm -'I which functions-as a camto-mo- .mentarily open switch20 for a Short interval u during which arm! is at the extreme ofits-travel, At this-time, if the feeding mecha'nismis functioningproperly, rod 4 will be in contact withstop 9 and thereby provide aparallel holding ,circuit forreIayiQ independent of switch 20. However,shouldrod A fail to be in contact with stop 9 at 3 this time due tofailure ofthe feeding mechanism or fo'rany other reason,,the holdingcircuit for relay 19 will be broken through .both parallel pathsandrelay Ill-will release.

Release'of relay 19 closes'theback contacts of. this relay, therebyclosing an energizing circuit through valve controlling relay-whichthereupon operates closing an energizing circuit for solenoid 40 whichoperates valve l8 through contacts 30 and a holding circuit for itselfthrough contacts :3l. The solenoid valve immediately op- What is claimedis:

;l. "In a 'machine'fed with conductive rod stock wherein-the end of therodis fed into said machine and a stop member stops the travel of saidrod when a predetermined length of rod has ,en-

tered the.machinewhereuponthe end of saidrod is cut ofl",thecombinationwith said machine of a, relay and angenergizing circuittherefor. said energizing circuit having two parallel branches,

one of said branches passing through said rod and stopin series,.aswitch in the other of said "branches, and afciam onacyclically-operating part of 'Jsaid machine 'engageable with said switchto open the same during that part of themachine cycle in which, said rod{is normally against said 'stop before 'being-cut-ofi, and a brakeoperated responsive tothe release of said relay to stop saidmachinewhenever said relay circuit is :brokenby said'cam'operated switch(when azparallel holding circuit for-said relay hasnot been establishedy said rod having I egigled said stop). 2. In a machine fe ithconductive rod stock wherein the endof the rod is Yfed intosaidmachineand a sto'p'member stops the travel'of said erates to supplycompressed'air to cylinder 1-6 and tighten the brake band thus applyingthe brake to stop the machine. The machine stopped almostinstantaneously so thatno serious damage can occur.

When relay I9 is released, it also opens'th e holding circuit forrelay23 through its front contact thus releasing relay,23 which opensthe motor a circuit.

"Whenthe'trouble has been remedied, the brake can be released bymomentarily opening brake- =release switch 32to release'relayjflandrelease the solenoid valve to close the compressed air line and openan exhaust port on the valve, :per-

mittingrelease of the compressed air-incylin'der [6. Switch -25 canthen'be momentarily closed to restart the motor.

It is sometimesnecessaryor desirable, to complete the electric circuitindependent of the rod or wirebeing fed into the machine. This is thecase, for example, when insulatingmaterials, such as Bakelite and otherplastics, are being worked upon.

Figures '2 and 3 show arrangements suitable for such cases. InFigure 2 asmall contact arm 55' is hinged or pivoted at 5| to-the machine frameand is grounded to it. Thefree end of arm has a contact which isnormally 'held'spaced fromstopfmemberi! by a spring 55. Astop pin 52limits the spacing. When the rod stock in strikes the free end of arm50'it moves'it'into contact with stop 9 to connect it and conductor-22to ground. In Figure 3 a plunger- 56 is supported-to slide in-aninsulating bushing 59 mounted on a bracket 53 onthe frame. Theend of theplunger is'in contact with thepushbutton -51 of amicroswitch-"'58. Whenrod 4a depressesthe plunger, the micro-switchis operated to connectground to conductor 22.

While specific embodiments of the invention have been described,,'itisintended to-cover the inventionbroadly within the spirit and scopelofthe appended claims.

rodwhen a predeterminedleng'th 'of rod-has en- .tered'theimachinewhereupon theend of said rod is cut off, the combination with saidmachine of a relay and an energizing circuit thereforrsaid energizingcircuit having two .parallel branches,

one of said v branches passing through said rod and stop in series, aswitch in the other of said branches, and a cam.on a cyclicallyoperating part of said machine engageablewith said switch to open thesameduring that part of the machine cycle-in whichl said rod-isnormallya ainst said stop beforebeing cut off, a'compressed air operatedbrake for-said machine and a solenoid-operated valve in the air supplyline therefor, and

an operating circuit for said valve passing through back contacts ofsaid relay.

3. In 'a-machine fed with conductive rod stock wherein'the'end oftheyrod'is fed into s'ai'd rnachine andav stop member stops the travelof said rod when a predetermined length ofrodhas entered the machinewhereupon the end of said rod is'cut off, the combination with saidmachine I of a relay and an energizing circuittherefor, said energizingcircuit having .twoparallel branches,

one of said brances passing through said rod and stop in series, aswitch in the other of said branches, and a cam on a cyclicallyoperating part of said machine engageable with said switch to openthesame during that'part of the machinecycle in which said rod is normallyagainst said step before being cut off,'a compressed air operated'brakefor said machine anda solenoid-operated valve in the air supplylinetherefor, and an operating circuit for saidwvalve'passing through backeontacts'oi said relay, an electricmotor the said rod to permit afurther section-of rod to-be advanced, a relay and an energizing circuittherefonsaid energizing circuit having twoparallel branches, one of saidbranches passing through said rod and'stop in series, a switch in theother of said branches, and a cam driven-bysaid motor for openingsaidswitch during a portion of each operassure ating cycle in which said rodend is normally in engagement with said stop, a brake for said drivingmotor and an energizing circuit therefor,

ing said rod and said stop in series therein, the other of said pathsincluding a switch, and a cam driven by said shaft and engaging theoperating arm of said switch to open the same for a portion oifi eachcycle of operation of said mechanism during which said rod is normallyin engagement with said stop, a brake for said power shaft, a brakeoperating mechanism therefor, and a control circuit for energizing saidbrake operating mechanism closed by the back contacts of said relay.

relay on release of said ERNEST W. HUEBNER. LOWELL E. PETERSON.

